1. Chapter 1 Cell Structure
Exam-Style-Questions-Answers :
Ans: B
4.[Fourth and Fifth Edition] Ans: i) nucleus
ii) smooth endoplasmic reticulum
rough endoplasmic reticulum
iii) 80S ribosomes
iv) chromatin
v) lysososmes
vi) golgi apparatus
vii) mitochondria
viii) centriole
ix) centrosome
x) vacuole(s)
a) [Fourth and Fifth Edition]Magnification is the number of times larger an image is compared with the real size of the object; the Light Microscope (LM) magnifies objects up to 1500 times, the Electron Microscope( EM )gives a very high magnification, it magnifies objects up to 100000 times; the magnifications of LM is obtained by multiplying the magnifying power of the objective and ocular lenses.
Resolution is the ability to distinguish between two separate points; maximum resolution of LM is 200nm. while that of EM is 0.5nm.
b) [Fourth and Fifth Edition]Light microscope uses light as a source of radiation; maximum resolution is 200nm; magnification up to 1500 times; glass lenses.
Electron microscope uses electron as a source of radiation; maximum resolution is 0.5nm; magnifications up to 100000 times; lenses electromagnets.
c) [Fourth and Fifth Edition]Nucleus and nucleolus both organelles found in Eukaryotic cells.
Nucleus is surrounded by a nuclear envelope; Nucleus controls cell activity.
Nucleolus not surrounded by a membrane; Nucleolus makes ribosomes.
d) [Fourth and Fifth Edition]Chromatin and chromosomes both found contain DNA ( and protein/histones/RNA) and both found in nucleus.
Chromatin is the form that exists between nuclear divisions;
Chromosomes are formed just before/during nuclear divisions.
e) [Fourth and Fifth Edition]An envelope consists of two membranes (one just inside/ outside the other); Envelopes only found in eukaryotic cells. e.g. the nuclear envelope.
A membrane is a thin (partially permeable ) barrier found around cells and some organelles; membranes found in/around all cells; e.g. the cell membrane, golgi body.
f) [Fourth and Fifth Edition]Both consist of flattened membrane-bound sacs; both found spreading through cytoplasm of eukaryotic cells;
The outer surfaces of Smooth ER are smooth ; have no ribosome on their surface; Smooth ER is involved in the synthesis of lipids/steroids.
The outer surfaces of Rough ER are rough; The presence of ribosomes on their surfaces; Rough ER transports proteins made by ribosomes on its surface.
g) [Fourth and Fifth Edition]Prokaryotes have no nucleus; prokaryotes have few organelles; Prokaryotes are smaller; division is by binary fission. ex. bacteria, archaea etc.
Eukaryotes have nucleus; Eukaryotes have many organelles, some membrane-bound; Eukaryotes are larger than prokaryote; division is by mitosis. ex. fungi, plants and animals.
h) [Fifth Edition]All cells have cell surface membrane; Cell surface membrane very thin; cell surface membrane not strong, is fragile; Cell surface membrane controls exchange between cell and environment; Cell surface membrane partially permeable.
Only some cells have cell walls; cell wall relatively thick; Cell wall strong, has straightening material; Cell wall protects cell from mechanical damage, from bursting by osmosis; Cell wall freely permeable.
i) [Fifth Edition]Both have a protective function;
Capsid found in viruses; Capsid made of protein;
Cell walls found in eukaryotes, plants, fungi and bacteria and some protoctists ; Cell walls made of polysaccharides, cellulose, chitin or murein.
j) [Fifth Edition]Both found in viruses;
Capsid is the protein coat surrounding the virus;
Capsomere is the protein coat is made of many protein subunits.
6. [Fourth and Fifth Edition]
a) Nucleolus, ribosome, centriole, centrosome, microtubule.
b) Lysosome, rough ER, smooth ER, golgi body, cilium, flagellum.
c) Nucleus, mitochondrion, chloroplast.
7. [Fourth and Fifth Edition]
a) Golgi apparatus
b) Nucleolus
c) Ribosome
d) ER/rough ER
e) Rough ER
f)Mitochondrion
g) Nucleus
h) Chloroplast
i) Centrosome
j) Nucleus
k) Membrane
l) Ribosome/Microtubule
m) Cilium/ flagellum.[Fifth Edition]
8. [ Fifth Edition]
Lebel ---- Name of Structure --------- Function
A Cell wall Maintains the shape of the plant cell;
prevents the cell bursting.
B Nucleus Contains the genetic material; the genetic code controls the
activities of the cell.
C Nuclear envelope Separates the DNA/ genetic material from the rest of the cell.
D Nucleolus Contains DNA that controls the manufacture of ribosomes.
E Cell Surface membrane Controls which substances can enter and leave the cells;
selectively permeable.
F --- Mitochondrion ------ Site of aerobic respiration; organelle where most ATP is made.
G ---- Chloroplast ----------- Contains Chlorophyll and is the site of photosynthesis; in the
Chloroplast grana/thylakoids , light- dependent reactions take
place, producing reduced NADP and ATP ; in the chloroplast
stroma, light independent reactions take place , producing
carbohydrates.
H ------- Sap vacuole ------------- Storage of solutes in a plant cell.
I ------- Tonoplast ---------------- Membrane around plant sap vacuole controlling which
substances can enter and leave the vacuole.
J ------- Starch grain ----------- Storage of Carbohydrate
9. [Fourth and Fifth Edition]
b)Quality of drawing: Sharp pencil used; more than half of available space used; clean continuous lines.
representative parts of main organelles drawn.
c) Mitochondria will appear circular if they are cut in transverse section.
d) i) A: Protein made on the ribosome is moving into the rough ER.
B: Rough ER buds off small vesicles; vesicles fuse to form the Golgi apparatus; therefore protein
moves into Golgi apparatus; protein may be modified inside Golgi apparatus.
C: Golgi apparatus buds off Golgi vesicles.
D: Golgi vesicles travel to cell surface membrane; Golgi vesicles fuseswith cell surface membrane protein enzyme leaves cell.
ii) Ribosome/ messenger RNA
iii) Nuclear pore.
iv) ATP.
10. [Fourth and Fifth Edition]
a) i) 100000g
ii) 1000g
iii) 10000g
b) Lysosomes are similar in size to/slightly smaller than mitochondria; therefore sediment is same g force; contaminate mitochondrial sample so cannot be sure whether effects due to mitochondria or lysosomes in any experiments.
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